Single and multiquantum vibrational relaxation of low and highly vibrationally excited levels of CO in collisions with N-2 is studied within the semiclassical coupled state method. The dynamics is followed using ab initio interaction potential for the short-range interaction and updated multipole expansions for the long range interaction. Compared to the previous study, a better agreement with the available experimental rate constants is obtained, particularly in the critical low temperature regime down to T = 80 K. Remarkable corrections are found for rate constants for single and multiquantum transitions between highly excited CO and N-2 molecules.